Which loudspeakers work best close to back wall?

Most of the Tekton speakers are front ported and can be placed closer to the back wall. I have the Lore's and most of the time are about 200mm ( about 7 inches ) from the wall. They can go closer but your room acoustics will ultimately tell you when they are too close to the wall.

If your NOT trying to fill a large room the Sonus Faber Toy Monitors are perfect for near wall placement.

My Classic Audio Loudspeakers are 6 inches from the rear wall. They image great with plenty of depth and I don't get a lot of boom- very natural bass, the best I have had in that room.

They are also very easy to drive.

The Audiokinesis speakers are quite flexible due to their adjustable rear port. I have put my pair close to the wall with great results. If need be I have plugs that can seal the port as well. Very reasonably priced as well.

If you can find them the Snell A-III speakers were designed for placement close to a wall. As were the Allison Ones.